The Sensex is now down 633 points at 15,495.The NSE Nifty is down 208 points at 4,664.Reliance Energy has slumped 8% to Rs 1,223, and BHEL has tumbled 7% to Rs 1,877.Reliance, Wipro and Bharti Airtel have plunged over 5.5% each to Rs 2,244, Rs 368 and Rs 765, respectively.Larsen & Toubro has slipped over 5% to Rs 2,790. Hindalco and NTPC have dropped 4.8% each to Rs 185 and Rs 185, respectively.ACC and TCS have shed 4.5% each at Rs 772 and Rs 788, respectively.Tata Steel, ONGC and DLF are down over 4% each at Rs 734, Rs 972 and Rs 684, respectively.Bajaj Auto has surged nearly 3% to Rs 2,152.